This application claims priority from Korean Patent Application NO. 10-2004-0045400 filed Jun. 18, 2004, hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an air conditioner for a vehicle, and more particularly, to an air conditioner for a vehicle that can independently control the temperatures of the front and rear areas and the left and right areas inside the vehicle, especially provided with a front seat air conditioning unit and a rear seat air conditioning unit such that the temperature of air discharged to the upper side portion of the rear seat air conditioning unit is lower than that of air discharged to the lower side portion thereof.
2. Background of the Related Art
Typically, a vehicle is provided with an air conditioner that heats or cools internal and external air to supply or circulate the heated or cooled air to the interior thereof, thereby keeping the air inside the vehicle at an appropriate temperature and making occupants inside the vehicle feel good.
The air conditioner for a vehicle generally includes a cooling device and a heating device. In more detail, the cooling device is constructed such that refrigerants, which are compressed by means of a compressor that is driven by the power of an engine, which are passed through a condenser, an expansion valve and the evaporator, and which flow into the compressor again, are heat-exchanged with the internal and external air introduced by a blower so as to make the air in the interior of the vehicle cool. The heating device is constructed such that the cooling water, which is used to keep the engine cool, is passed through the heater core, and is returned to the engine. Thereafter, the cooling water is heat-exchanged with the internal and external air flowing out by the blower so as to make the air in the interior of the vehicle heated.
In the conventional air conditioner for the vehicle, however, vent outlets and floor outlets that supply the air to the inside of the vehicle are disposed on the front sides of the front seats, which decreasing the cooling and heating efficiencies for the rear seats substantially.
To solve the above-mentioned problems, in addition to the main air conditioner that is mounted in an engine room, a rear air conditioner is provided at the trunk room, which allows the heating and cooling efficiencies for the rear seats to be relatively higher than those when only the main air conditioner is mounted inside the vehicle. However, a substantially large area is occupied to mount such the rear air conditioner in the trunk room, which causes the available size of the trunk room to be much reduced. Also, a duct is extended from the trunk room to the rear seat such that the structure for installation of the rear air conditioner becomes complicated and at the same time the heated air or the cooled air is easily lost, which drastically reduces the heating and cooling efficiencies for the rear seats.
To solve such the above-mentioned problems occurring in the conventional rear air conditioner, there is provided Korean Publication No. 2001-0059264 that is filed by the same applicant as the present invention, in which a main air conditioner is provided with an auxiliary air conditioning unit that is operated independently of the main air conditioner in order to efficiently achieve the cooling and heating for the rear seats.
FIG. 1 is a schematic perspective view of showing a conventional air conditioner 1 for a vehicle provided with a main air conditioner 10 and an auxiliary air conditioner 20 therein, and FIG. 2 is a sectional view of showing the auxiliary air conditioner 20. As shown, the main air conditioner 10 blows air through wind shield openings 14′a and 14′b, center and side openings 12′a and 12′b, and floor openings 13′a and 1′b, and the auxiliary air conditioner 20 blows air through vent outlets 22a hand 22b and floor outlets 23a and 23b. 
According to the prior art, the auxiliary air conditioner 20 includes an auxiliary evaporator and an auxiliary heater core, and in this case, respective working fluids that are passed through the auxiliary evaporator and the auxiliary heater core are supplied from the main air conditioner.
In the conventional auxiliary air conditioner, however, the auxiliary heater core is not separated by a predetermined distance from the inner surface of a casing for the auxiliary air conditioner such that the air flowing out from the auxiliary evaporator is necessarily passed through the auxiliary heater core. This prevents a bi-level mode where the temperatures of air flowing to the vent outlets and the floor outlets are different from being conducted.
If the auxiliary heater core is separated by the predetermined distance from the inner surface of the casing for the auxiliary air conditioner, the bi-level mode is carried out such that the temperatures of air flowing to the vent outlets and the floor outlets are different from each other. In this case, cool air is descended and hot air is ascended by the feature of air convection, such that the warm air in the auxiliary air conditioner flows out through the vent outlets and the cool air therein flows out through the floor outlets. At this time, the relatively high temperature of air is not mixed with the relatively low temperature of air, which provides a high degree of refreshing sense to a user.
Even though a part of air passed through the auxiliary evaporator bypasses the auxiliary heater core and is then discharged to the outlets through the inner side of the casing for the auxiliary air conditioner and another part of the air is discharged to the outlets through the auxiliary heater core, it is not possible to achieve the control of the air flowing in such a manner that relatively cool air is discharged to the vent outlets and relatively warm air is discharged to the floor outlets.
According to the prior art, in addition, the auxiliary air conditioner for the rear seats inside the vehicle is not allowed to drive individually the left and right areas for the rear seats, thereby making it impossible to have a multi-zone type of air conditioner where the control of the temperatures for the left and right areas is conducted successfully. To obtain the multi-zone type of air conditioner, preferably, the auxiliary air conditioner has to be mounted for the left and right areas, respectively. This of course causes the number of parts and production processes to be considerably increased to make the production costs greatly high. This also causes the whole installation space of the air conditioner to be substantially enlarged, which prevents the equipment from being compact and keeps the working efficiencies for the installation of the equipment from being improved.
Another conventional auxiliary air conditioner is disclosed in Japanese Patent Laid-Open Publication No. 2000-168338 as shown in FIG. 3, wherein an auxiliary air conditioner 30 serves to provide an appropriate temperature difference between the air flowing to the vent outlets and the air flowing to the floor outlets. However, the auxiliary air conditioner 30 does not have any space portion where the air that is passed through the evaporator 32 and the air that is passed through the heater core 33 are mixed sufficiently before supplying to the outlet 34, such that a cool air guiding means and a warm air guiding means should be formed in the auxiliary air conditioner casing 31. This makes the shape of the casing 31 more complicated. Also this makes it difficult to control the temperature of the discharging air and to control individually the temperatures of the left and right areas.